1. Field of the Invention
The present invention relates to a liquid jet recording head that jets a liquid such as a recording liquid or the like from discharge ports (orifices) and forms droplets.
2. Description of the Related Art
Recording apparatuses having functions of a printer, a copier, a facsimile or the like, or recording apparatuses used as a multifunction electronic machine including a computer, a word processor and the like, or as an output device of a work station, are structured so as to record images on a medium to be recorded such as a recording paper, a plastic thin plate or the like on the basis of image information. These kinds of recording apparatuses can be classified into an ink jet system, a wire dot system, a thermal system, a laser beam system and the like in accordance with the recording system.
In a serial type recording apparatus that uses a recording system main-scan in a direction intersecting a conveying direction (sub-scanning direction) of the medium to be recorded, the medium to be recorded is set at a predetermined recording position. Thereafter, by repeating the operations of recording (main scan) the image by recording means loaded on a carriage moving along the medium to be recorded, and feeding a predetermined amount of paper (pitch-feeding) after one line has been recorded, and thereafter, recording (main scan) the image of the next line, recording of the entire image on the medium to be recorded is carried out.
On the other hand, in a line type recording apparatus in which recording is carried out by only sub-scanning in the conveying direction of the medium to be recorded, the medium to be recorded is set at a predetermined recording position. By sequentially repeating operations, after recording of one line is collectively carried out, of feeding a predetermined amount of paper (pitch feeding) and then collectively recording the next line, recording of the entire image is carried out on the medium to be recorded.
As typical recording apparatuses which use such serial type and line type liquid jet systems, there is a recording apparatus in which a liquid jet recording head is loaded. Such a recording apparatus is a so-called non-impact recording system recording apparatus, and can carry out high-speed recording and recording for various types of median to be recorded, and has the features that noise at the time of recording does not substantially arise.
Among such liquid jet recording heads, in particular, a liquid jet recording head which discharges a recording liquid by utilizing thermal energy can form a flow path at a high density and can be made more compact, by forming an electrical thermal converter, an electrode, a flow path wall, a top plate, an orifice plate and the like which are film-formed on a substrate through a semiconductor process such as etching, vacuum deposition, sputtering or the like.
As this type of liquid jet recording head, a jetting method using electrical thermal converting elements has been known as a typical jetting method, there is a method in which recording is carried out on the medium to be recorded by discharging droplets from extremely small discharge ports.
Hereinafter, one example of a conventional liquid jet recording head will be described with reference to the drawings. Generally, the liquid jet recording head is structured by having a recording unit for forming droplets and a recording liquid supplying section for supplying a recording liquid to the recording unit.
A perspective view of the exterior of the conventional liquid jet recording head is shown in FIG. 21, and an exploded perspective view of the conventional liquid jet recording head is shown in FIG. 22.
As shown in FIG. 21 and FIG. 22, the conventional liquid jet recording head has recording element substrates 201 discharging droplets, a supporting substrate 202 supporting the recording element substrates 201, wiring sheets 203 and a terminal wiring substrate 205 which are for supplying a recording signal to the recording element substrates 201, and a flow path forming member 206 having a flow path for supplying the recording liquid to the recording element substrates 201.
The recording element substrate 201 has an unillustrated electrical thermal converting element (heater) which is an energy generator, and discharge ports 201a provided at positions facing the electrical thermal converting element. Further, the recording element substrates 201 are joined so as to be laminated on the supporting substrate 202 formed from, for example, aluminum or ceramics.
On the supporting substrate 202, the wiring sheets 203, which are for transmitting electric pulse signals to the recording element substrates 201 and which are formed from TAB (Tape Automated Bonding), FPC (Flexible Printed Circuit) or the like, are adhered. The recording element substrates 201 and the wiring sheets 203 are electrically connected by wire bonding, lead bonding or the like.
Further, one end of the wiring sheet 203 is electrical connected to the terminal wiring substrate 205 for electrically connection to a drive controlling section (not shown) which the recording apparatus has. The terminal wiring substrate 205 is formed from a PWB (Printed Wiring Board), TAB, FPC or the like. A contact system connecting terminal 204, to which the drive controlling section is electrically connected, is provided on the main surface of the wiring substrate 205.
Although not illustrated, bosses provided at the flow path forming member 206 are inserted into holes of the terminal wiring substrate 205, and the flow path forming member 206 and the terminal wiring substrate 205 are joined and fixed by heat-welding, an adhesive or the like.
Also, the flow path forming member 206 has recording liquid supplying paths 206a for supplying recording liquid to the recording element substrates 201.
Moreover, due to the supporting substrate 202 being joined and fixed to the flow path forming member 206, recording liquid stored in an unillustrated recording liquid tank is supplied to the recording element substrates 201 through the recording liquid supplying paths 206a of the flow path forming member 206.
The liquid jet recording head described above has a structure in which the plurality of recording element substrates 201 are provided so as to be laminated on the single supporting substrate 202. However, as another structure, there is also a liquid jet recording head in which the single recording element substrate 201 is provided so as to be laminated on the supporting substrate 202.
As described above, when the liquid jet recording head at which the single recording element substrate 201 is mounted is loaded in a recording apparatus, there are a form in which the single liquid jet recording head is loaded and a form in which the plurality of liquid jet recording heads are loaded.
In the liquid jet recording head which is structured such that the plurality of recording element substrates 201 are laminated on the supporting substrate 202, because the individual recording element substrates 201 are laminated by semiconductor mounting technique, the relative positions between the respective recording element substrates are precisely disposed on the supporting substrate. On the other hand, in a form in which the plurality of liquid jet recording heads, in which a single recording element substrate is laminated on the supporting substrate, are loaded in the recording apparatus, the plurality of liquid jet recording heads are individually and respectively positioned on the carriage (or a accommodating portion for the liquid jet recording heads) of the recording apparatus. Therefore, the accuracy of the relative positions between the recording element substrates is a value in which the positional accuracy of the respective recording element substrates and the positional accuracy of loading the respective liquid jet recording heads at the carriage are added.
As described above, the liquid jet recording head using the electrical thermal converting element has a pressure chamber in which the electrical thermal converting element is provided. Thermal energy is applied to the recording liquid by applying an electrical pulse which is the recording signal to the pressure chamber. The bubble pressure at the time of bubbling (at the time of film boiling) of the recording liquid caused by the change of the phase of the recording liquid at that time is utilized for discharging the recording droplets.
In addition, in a case of the liquid jet recording head using the electrical thermal converting system, there are a method in which recording liquid is discharged parallel to the substrate on which the electrical thermal converting elements are aligned (hereinafter, called an edge shooter), and a method in which recording liquid is discharged perpendicular to the substrate on which the electrical thermal converting elements are aligned (hereinafter, called a side shooter).
In such a liquid jet recording head, when the temperature of the recording element substrate has excessively risen, during recording, abnormalities arise in electric pulse which is the recording signal, the bubbling state of the recording liquid or the like, and there is the concern that the recording state will deteriorate. Therefore, generally, some heat discharging countermeasures are applied to the interior of the liquid jet recording head.
As a heat discharging countermeasure, in the case of the edge shooter type liquid jet recording head, as described above, there are many cases in which a supporting substrate formed from a material such as, for example, aluminum, an aluminum alloy, ceramics or the like is adhered as a heat discharging member on the rear surface of the recording element substrate formed from an Si material.
On the other hand, in a case of the side shooter type liquid jet recording head, as a simple heat discharging countermeasure, there is a method in which heat discharge is carried out by the recording liquid which is discharged through the rear surface of the recording element substrate from the recording liquid storing medium. As another heat discharging countermeasure, in the side shooter type liquid jet recording head in which it is easy for the temperature to rise because the recording elements highly dense, there are methods such as a supporting substrate, which serves as a heat discharging member at which to contact surface area with the recording element substrate can be relatively large, is provided, and the recording element substrate is joined to and fixed on the supporting substrate or the like.
As described above, in the case of the recording apparatus of the form in which the plurality of liquid jet recording heads at which a single recording element substrate is mounted are loaded so as to be aligned on the carriage, there is the problem that the width of the entire liquid jet recording head is wide.
Further, on the other hand, because spaces partitioning the respective liquid jet recording heads are formed on the carriage, as compared with a recording apparatus at which is loaded an liquid jet recording head at which a plurality of recording element substrates are mounted, the width of the carriage is wider, which is a factor in causing the entire recording apparatus to become large.
Furthermore, in a liquid jet recording head at which a plurality of recording element substrates are mounted, due to some of the electric wiring paths being in common, the total number of the connecting terminals on the liquid jet recording head can be reduced. On the other hand, in a liquid jet recording head at which a single recording element substrate is mounted, it is difficult to make the connecting terminals be used in common. Therefore, the total number of the connecting terminals is larger than that of the liquid jet recording head at which a single recording element substrate is mounted, and due to the layout of these connecting terminals, the mounting space which the entire liquid jet recording head occupies on the carriage becomes large.
Moreover, in the conventional liquid jet recording head, because it is necessary to ensure, at the flow path forming member, a holding region for holding the terminal wiring substrate having the connecting terminals, the flow path forming member becomes large. Accompanying this increase in size of the flow path forming member, in the manufacturing process of the liquid jet recording head, the installation space which the manufacturing line of the flow path forming member occupies is large, and productivity deteriorates.
Thus, an object of present invention is to provide a liquid jet recording head which aims to make the liquid jet recording head compact and which has improved productivity.
In order to achieve the above-described object, the liquid jet recording head of the present invention has a recording element substrate at which a plurality of recording elements for discharging recording liquid are provided; a flexible wiring sheet which is provided so as to surround a periphery of the recording element substrate and which is for transmitting a recording signal to the recording element substrate; a wiring substrate having a terminal portion which is electrically connected to one end portion of the wiring sheet and is for input of recording signal from an exterior; and a flow path forming member at which recording liquid supplying paths for supplying recording liquid to the recording element substrate are provided. One end portion of the wiring substrate is supported by the flow path forming member. Further, when the flow path forming member is joined to a holder member which detachably holds a recording liquid storage unit in which recording liquid is stored at the interior thereof or a recording liquid storage tank in which recording liquid is stored at the interior thereof, due to side end portions facing another end portion of the wiring substrate being respectively inserted into and engaged with a set of engaging grooves provided at the recording liquid storage unit or the holder member in a state in which the one end portion of the wiring substrate is supported by the flow path forming member, the wiring substrate is held by the flow path forming member and the recording liquid storage unit or the holder member.
Further, the liquid jet recording head relating to the present invention is structured by connecting the holder member, which detachably holds the recording liquid storage unit in which recording liquid is stored at the interior thereof or the recording liquid storage tank in which recording liquid is stored at the interior thereof, to a recording unit for carrying out recording on a medium to be recorded, the recording unit comprising: a recording element substrate at which a plurality of recording elements for discharging recording liquid are provided; a flexible wiring sheet which is provided so as to surround a periphery of the recording element substrate and which is for transmitting a recording signal to the recording element substrate; a wiring substrate having a terminal portion which is electrically connected to one end portion of the wiring sheet and is for input of recording signal from an exterior; a flow path forming member at which recording liquid supplying paths for supplying recording liquid to the recording element substrate are provided; and a porous member for filtering recording liquid. The one end portion of the wiring substrate is supported by the flow path forming member, and another end portion thereof is respectively engaged with a set of engaging grooves provided at the recording liquid storage unit or the holder member. The wiring substrate is thereby held by the flow path forming member and the recording liquid storage unit or the holder member.
In accordance with the liquid jet recording head which is structured as described above relating to the present invention, as compared with a structure in which the wiring substrate is fixed to the flow path forming member by, for example, heating and press-fixing, there is no need to provide spaces for forming holes for heating and press-fixing on the wiring substrate, and the width of the wiring substrate can be made narrow. In accordance therewith, the width of the entire liquid jet recording head corresponding to the width of the wiring substrate can be made compact.
Further, in accordance with this liquid jet recording head, when the flow path forming member and the recording liquid storage unit or the holder member are assembled, the one end portion of the wiring substrate is inserted into and held at the engaging grooves provided at the recording liquid storage unit or the holder member. Therefore, it is possible to omit a manufacturing process for fixing the wiring substrate, and an improvement in the productivity can be achieved. Moreover, because the wiring substrate can be easily removed from the recording liquid storage unit or the holder member, the disassembly work in which the liquid jet recording head is disassembled into the recording unit and the recording liquid storage unit or the holder member can be easily carried out, and the recycling performance can be improved.
Further, in the liquid jet recording head relating to the present invention, the wiring substrate is held over the flow path forming member and the recording liquid storage unit or the holder member. In accordance therewith, only the other end portion side of the wiring substrate is held by the flow path forming member. Namely, in the flow path forming member, there is no need to provide a receiving space over the entire region of the terminal wiring substrate as in the structure of the conventional liquid jet recording head. As a result, in the flow path forming member, the degrees of freedom of designing are improved, and it is possible to attain optimization of the shape of the member, and it is possible to achieve compactness. Therefore, the space for installing the flow path forming member is made small, and the productivity is markedly improved.
Further, in the liquid jet recording head relating to the present invention, positioning portions which position the wiring substrate respectively with respect to three axial directions are provided at the recording unit. In accordance therewith, portions which affect discharging performance and mechanical accuracy of the liquid jet recording head can be concentrated at the recording unit. Accordingly, because the minimum functions which are necessary for storing the recording liquid may be provided at the recording liquid storage unit, it is possible to select inexpensive materials and form the recording liquid storage unit. Further, in the same way, because the function of detachably holding the recording liquid storage tank may be provided at the holder member, it is possible to select inexpensive materials and form the holder member. Namely, due to the functions and parts accuracy being separated and areas of which functions and parts accuracy are required being concentrated at the recording unit in this way, the productivity is markedly improved, and as a result, a high-performance liquid jet recording head can be inexpensively manufactured.
Further, in accordance with the liquid jet recording head relating to the present invention, a joining piece having elasticity is provided at one of the recording unit and the recording liquid storage unit or the holder member, and a joining portion to which the joining piece is joined is provided at the other. In accordance therewith, the recording unit and the recording liquid storage unit or the holder member can be easily disassembled as compared with a structure in which the members are joined by screws, an adhesive or the like, and the recycling performance is improved. Furthermore, because improvement of productivity can be achieved, the liquid jet recording head can be inexpensively manufactured.
Further, in the liquid jet recording head relating to the present invention, at the recording unit, projection portions are respectively formed at positions facing one another, with the porous member being nipped between them. Distal ends of the projection portions with respect to the thickness direction of the porous member are formed so as to project more than the end surface of the porous member. In accordance therewith, in the manufacturing process of the liquid jet recording head, because the porous member provided at the flow path forming member is protected by the respective projection portions, it is possible to easily handle the flow path forming member, and the productivity of the liquid jet recording head is improved.
Further, the liquid jet recording head relating to the present invention has a recording element substrate at which a plurality of recording elements for discharging recording liquid are provided; a wiring sheet which is provided so as to surround the periphery of the recording element substrate and has flexibility and is for transmitting a recording signal to the recording element substrates; a wiring substrate having a terminal portion which is electrically connected to one end portion of the wiring sheet and is for input of a recording signal from an exterior; and a flow path forming member at which recording liquid supplying paths for supplying recording liquid to the recording element substrate are provided. The liquid jet recording head also has holding means for holding one end portion of the wiring substrate in a state in which it is curved from one of the mutually-facing side end portions of one end portion toward the other. Then, when the flow path forming member is joined to the holder member which detachably holds a recording liquid storage unit in which a recording liquid is stored at the interior thereof or a recording liquid storage tank in which a recording liquid is stored at the interior thereof, due to the opposing side end portions of the end portion of the wiring substrate being respectively inserted into and engaged with the set of engaging grooves provided at the recording liquid storage unit or the holder member in a state in which the one end portion of the wiring substrate is supported by the flow path forming member, the wiring substrate is held by the flow path forming member and the recording liquid storage unit or the holder member.
Further, the liquid jet recording head relating to the present invention is structured by connecting the holder member, which detachably holds the recording liquid storage unit in which recording liquid is stored at the interior thereof or the recording liquid storage tank in which recording liquid is stored at the interior thereof, to a recording unit for carrying out recording on a medium to be recorded, the recording unit comprising: a recording element substrate at which a plurality of recording elements for discharging recording liquid are provided; a flexible wiring sheet which is provided so as to surround a periphery of the recording element substrate and which is for transmitting a recording signal to the recording element substrate; a wiring substrate having a terminal portion which is electrically connected to one end portion of the wiring sheet and is for input of recording signal from an exterior; a flow path forming member at which recording liquid supplying paths for supplying recording liquid to the recording element substrate are provided; and a porous member for filtering recording liquid. Due to one end portion of the wiring substrate being held by the holding means in a state it which it is curved from one of the side mutually-opposing end portions of the one end portion to the other side, and due to the other end portion of the wiring substrate being respectively engaged with the set of engaging grooves provided at the recording liquid storage unit or the holder member, the wiring substrate is held by the flow path forming member and the recording liquid storage unit or the holder member.
Further, the liquid jet recording head relating to the present invention is structured by connecting the holder member, which detachably holds the recording liquid storage unit in which recording liquid is stored at the interior thereof or the recording liquid storage tank in which recording liquid is stored at the interior thereof, to a recording unit for carrying out recording on a medium to be recorded, the recording unit comprising: a recording element substrate at which a plurality of recording elements for discharging recording liquid are provided; a flexible wiring sheet which is provided so as to surround a periphery of the recording element substrate and which is for transmitting a recording signal to the recording element substrate; a wiring substrate having a terminal portion which is electrically connected to one end portion of the wiring sheet and is for input of recording signal from an exterior; a flow path forming member at which recording liquid supplying paths for supplying recording liquid to the recording element substrate are provided; and a porous member for filtering recording liquid. The set of engaging grooves, in which the opposing side end portions of the one end portion of the wiring substrate are respectively inserted and engaged, are provided at the recording liquid storage unit or the holder member. Furthermore, the flow path forming member has positioning members for positioning the one end portion of the wiring substrate with respect to the flow path forming member; and a set of engaging portions respectively engaging with the opposing both side end portions of the one end portion of the wiring substrate. Then, in a state in which the one end portion of the wiring substrate is held at the flow path forming member by the positioning portions and the set of engaging portions, due to the another end portions of the wiring substrate being engaged with the set of engaging grooves, the wiring substrate is held by the flow path forming member and the recording liquid storage unit or the holder member.
Further, in the liquid jet recording head relating to the present invention, a projection, which is positioned at a substantial center on the straight line connecting the set of engaging portions and contacts the rear surface of the one end portion of the wiring substrate, is provided at the recording unit. In accordance therewith, it is possible to hold the wiring substrate in a curved state. Therefore, in the liquid jet recording head, due to the wiring substrate being held in a curved state, in the manufacturing process of the liquid jet recording head, when an external force in a bending direction is applied to the other end portion of the wiring substrate (the end portion which is at the side opposite one end portion side held by the flow path forming member), because the engaged state by the engaging portions is easily cancelled, the wiring substrate or the recording unit is prevented from being broken.
Further, in the liquid jet recording head relating to the present invention, a distance, in the direction of the thickness of the wiring substrate, between the engaging surfaces at which the engaging portions are engaged with the wiring substrate and the contacting surface at which the projection contacts the wiring substrate, is thinner than the thickness of the wiring substrate. In accordance therewith, it is possible to hold the wiring substrate so as to be curved well.